What is Aerotoxic Syndrome?
Aerotoxic Syndrome is the term for the illness caused by exposure to contaminated air in jet aircraft.
This term was first introduced in a published paper in 1999 by Dr Harry Hoffman (USA), Professor Chris Winder (Australia) and Jean Christophe Balouet PhD (France) in their paper, “Aerotoxic Syndrome: Adverse health effects following exposure to jet oil mist during commercial flights.”
How is Aerotoxic Syndrome caused?
A supply of pressurised air is required by humans to sustain life at high altitude. This air is supplied direct from the compressor section of the jet engine and is known as ‘bleed air’. Unfiltered bleed air is mixed inside the aircraft with recirculated cabin air at a ratio of 50/50. Although the recirculated is subsequently filtered, all of the bleed air which originates from the jet engines is unfiltered.
Jet engines operate at higher temperatures and therefore use synthetic chemicals as oils. ‘Wet seals’ are used to keep the oil and bleed air apart; however, the seals are designed to leak, thus allowing small amounts of oil to be detected in the bleed air. Furthermore seals, like any mechanical component, slowly wear out and their efficiency then gradually declines, thus allowing more and more oil into both the cockpit and cabin air.
The seals can also suddenly fail resulting in visible fumes and/or smoke entering the cockpit and cabin. This is known as an ‘oil fume event’. However, it has recently been termed as an ‘odour event’ by authorities who are eager to distract attention from a fundamental design flaw.
Engine oil contains 3-5% organophosphate additives as anti-wear agents; it is chemically altered due to the extremely high temperatures in the jet engine. Auxiliary Power Units also produce unfiltered bleed air and cause particularly severe oil fume events (often visible), often after start up.
Exposure to contaminated cabin air can have both short and long term ill health on individuals.
This can be based on many factors: levels and types of toxic chemicals present during an oil fume event (which may be visible or invisible) and occur on any flight; previous exposure history to contaminated air; genetic make-up; age; medical conditions; and potentially any medication being taken.
Those who have been subject to toxic oil exposure normally complain of headaches, breathing difficulties, muscle aching and exhaustion. For those who suffer full Aerotoxic Syndrome symptoms (where repeated exposures of toxic chemicals attack the central nervous system) symptoms are mainly neurological but are many and varied. Aerotoxic Syndrome is frequently misdiagnosed and mistreated by doctors unfamiliar with a hidden cause of poisoning and then mistreated with anti-depressants and other drugs.
So-called jet lag is not caused by crossing times zones, but a one-off acute poisoning or repeated low-level exposures by chemicals. These chemicals produce indistinguishable symptoms to jet lag; however, commercial jets cannot obviously be officially blamed as a cause of mass ill health in aircrew and passengers.
Few victims will work out the cause of their ill health, as being gassed is subtle and mostly invisible.
Additionally, despite repeated calls, there are no poison detectors fitted in modern jets. Instead, there are just noses for a sense of smell and eyes to see possible oil fumes. Many former aircrew victims speak of being like “zombies”, in a “vegetative state” or “permanently intoxicated”, but single poisonings to passengers have occurred. If you have flown on an airliner and then experienced unexplained ill health symptoms, please click here.